Improved mode of preventing incrustation in steam-boilers



I UNITED STATES PATENT QFFICEO LEWVIS BAIRD, OF CAMBRIDGE,MASSACHUSETTS,

IMPROVED MODE 0F PREVENTING INCRUSTATION IN STEAM-BOILERS.

Specification forming part of Letters Patent No. 34. l 88. dated January21, 1862.

To all whom it may concern:

Be it known that I, LEwIs BAIRD, of Cambridge, in the county ofMiddlesex and State of Massachusetts, have invented a new Method ofPreventing the Incrustation of Steam-Boilers, and of scaling the sameafter they have become incrusted, of which the following is a full,clear, and exact description.

My invention has for its object to prevent the incrustation ofsteam-boilers where water holding calcareous or saline matters insolution is used and it consists in the introduction within the boilerof tobacco, or of a decoction or preparation of the same. This may bedone in various ways. For example, tobacco in the leaf, or pressed orotherwise manufactured or prepared, may be introduced directly into theboiler, it being so secured in a bag of canvas, or otherwise, that itshall not get to the machinery or beneath the valves; or a decoction oftobacco may be made and introduced at intervals with the feed-water, orby a separate injecting-pinup employed for the purpose.

The form in which I prefer to apply the tobacco is that of aconcentrated extract, for

which Letters Patent of the United States were sufficient to cover theinterior surface of the boiler with a glazing or varnish whicheffectually prevents the adhesion of any incrustation upon the metal.After this covering or glaze is once produced a considerable reductionof the quantity of the tobacco may be made as compared with the quantityof water employed, it being simply necessary to preserve the glazed orvarnished surface thus produced, and for this purpose a smallerproportion of the tobacco is required. The quan tity of future additionsthus required to preserve the boiler entirely free and clean will varysomewhat with the extent to which the water is changed by blowing off.No definite rule can therefore be given, but it will never equal thequantity required at first (where sea water is employed) for the purposeof first preparing the surface of the boiler. It is manifest also thatthe amount of tobacco required in any case will vary with the density ofthe water employed, or with the different amounts of saline orcalcareous matter which it holds in solution. The above proportion,however, I have found to be entirely suflicient with those waters withwhich I have experi-.

mented,while no injurious results follow where the amount of tobaccoemployed is very considerably increased.

This introduction of tobacco into steamboilers in any of the ways abovedescribed I have found to be a perfect preventative of incrustation, andwhere the boiler has previously become incrusted it will effectuallyscale and cleanse it.

What I claim as my invention, and desire to secure by Letters Patent, is

The employment of tobacco, or a decoction or extract of the same, forthe purpose of preventing the incrustation of steam-boilers or ofremoving the scale therefrom.

LEWIS BAIRD.

lVitnesses:

THOS. It. ROACH, SAM. COOPER.

